Sometimes,
AutoPrereqs is a little overzealous and finds a prereq that you wrote inline or have in your ./t directory.
Although AutoPrereqs should grow more accurate over time,
and avoid these mistakes,
it's not perfect right now.
CheckPrereqsIndexed will check every required package against the CPAN index to ensure that they're all real,
installable packages.

If any are unknown,
it will prompt the user to continue or abort.

Previously,
CheckPrereqsIndexed queried CPANIDX,
but it now queries cpanmetadb.
This behavior may change again in the future,
or it may become pluggable.
In the meantime,
this makes releasing while offline impossible...
but it was anyway,
right?

This is an arrayref of regular expressions.
Any module names matching any of these regex will not be checked.
This should only be necessary if you have a prerequisite that is not available on CPAN (because it's distributed in some other way).